boringssl/ssl/s3_meth.c
David Benjamin b6a0a518a3 Simplify version configuration.
OpenSSL's SSL_OP_NO_* flags allow discontinuous version ranges. This is a
nuisance for two reasons. First it makes it unnecessarily difficult to answer
"are any versions below TLS 1.3 enabled?". Second the protocol does not allow
discontinuous version ranges on the client anyway. OpenSSL instead picks the
first continous range of enabled versions on the client, but not the server.

This is bizarrely inconsistent. It also doesn't quite do this as the
ClientHello sending logic does this, but not the ServerHello processing logic.
So we actually break some invariants slightly. The logic is also cumbersome in
DTLS which kindly inverts the comparison logic.

First, switch min_version/max_version's storage to normalized versions. Next
replace all the ad-hoc version-related functions with a single
ssl_get_version_range function. Client and server now consistently pick a
contiguous range of versions. Note this is a slight behavior change for
servers. Version-range-sensitive logic is rewritten to use this new function.

BUG=66

Change-Id: Iad0d64f2b7a917603fc7da54c9fc6656c5fbdb24
Reviewed-on: https://boringssl-review.googlesource.com/8513
Reviewed-by: David Benjamin <davidben@google.com>
2016-06-30 21:56:01 +00:00

178 lines
5.4 KiB
C

/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.] */
#include <openssl/ssl.h>
#include "internal.h"
static uint16_t ssl3_version_from_wire(uint16_t wire_version) {
return wire_version;
}
static uint16_t ssl3_version_to_wire(uint16_t version) { return version; }
static const SSL_PROTOCOL_METHOD TLS_protocol_method = {
0 /* is_dtls */,
SSL3_VERSION,
TLS1_3_VERSION,
ssl3_version_from_wire,
ssl3_version_to_wire,
ssl3_new,
ssl3_free,
ssl3_get_message,
ssl3_read_app_data,
ssl3_read_change_cipher_spec,
ssl3_read_close_notify,
ssl3_write_app_data,
ssl3_dispatch_alert,
ssl3_supports_cipher,
ssl3_init_message,
ssl3_finish_message,
ssl3_write_message,
ssl3_send_change_cipher_spec,
ssl3_expect_flight,
ssl3_received_flight,
};
const SSL_METHOD *TLS_method(void) {
static const SSL_METHOD method = {
0,
&TLS_protocol_method,
};
return &method;
}
const SSL_METHOD *SSLv23_method(void) {
return TLS_method();
}
/* Legacy version-locked methods. */
const SSL_METHOD *TLSv1_2_method(void) {
static const SSL_METHOD method = {
TLS1_2_VERSION,
&TLS_protocol_method,
};
return &method;
}
const SSL_METHOD *TLSv1_1_method(void) {
static const SSL_METHOD method = {
TLS1_1_VERSION,
&TLS_protocol_method,
};
return &method;
}
const SSL_METHOD *TLSv1_method(void) {
static const SSL_METHOD method = {
TLS1_VERSION,
&TLS_protocol_method,
};
return &method;
}
const SSL_METHOD *SSLv3_method(void) {
static const SSL_METHOD method = {
SSL3_VERSION,
&TLS_protocol_method,
};
return &method;
}
/* Legacy side-specific methods. */
const SSL_METHOD *TLSv1_2_server_method(void) {
return TLSv1_2_method();
}
const SSL_METHOD *TLSv1_1_server_method(void) {
return TLSv1_1_method();
}
const SSL_METHOD *TLSv1_server_method(void) {
return TLSv1_method();
}
const SSL_METHOD *SSLv3_server_method(void) {
return SSLv3_method();
}
const SSL_METHOD *TLSv1_2_client_method(void) {
return TLSv1_2_method();
}
const SSL_METHOD *TLSv1_1_client_method(void) {
return TLSv1_1_method();
}
const SSL_METHOD *TLSv1_client_method(void) {
return TLSv1_method();
}
const SSL_METHOD *SSLv3_client_method(void) {
return SSLv3_method();
}
const SSL_METHOD *SSLv23_server_method(void) {
return SSLv23_method();
}
const SSL_METHOD *SSLv23_client_method(void) {
return SSLv23_method();
}